Apparatus for separating gold



Oct. 18, 1938. F. w. BRINTNALL 2,133,271

APPARATUS FOR SEPARATING GOLD Filed Dec. 16, 1935 4 Sheets-Sheet 1 I? I B gls k i E A Q j 59 TI 11111111: "92" I: ZZZ" 21 52255-51119 M f\ '1 INVENTOR Halli ,Brz'xZnaZZ.

' ATTORNEY.

Oct. 18, 1938. w BRlNTNALL 2,133,271

APPARATUS FOR SEPARATING GOLD Filed Dec. 16, 1935 4 Sheets-Sheet 2 Z8 Fl 69 mmvron w h 4 ATTORNEY.

Oct. 18, 1938. F. w. BRINTNALL 2,133,271

APPARATUS FOR SEPARATING GOLD 4 Sheets-Sheet 5 Filed Dec. 16, 1935 INVENTOR. 77x02} .Brz'ninall.

ATTORNEY.

Oct. 18, 1938. F. w. BRINTNALL APPARATUS FOR SEPARATING GOLD Filed Dec. 16, 1935 4 Sheets-Sheet 4 7 INVENTOR. Fizz/f llflrz'kirzazl BYM W A TTORNE Y.

UNITED STATES PATENT OFFICE APPARATUS FOR SEPARATING GOLD Frank W. Brintnall, Detroit, Mich assiznor to Ulysses S. Bratton, Jr., Detroit, Mich.

Application December 16, 1935, Serial No. 54,781

23 Claims.

This invention relates to improvements in apparatus for refining gold.

Among the objects of my invention are to provide an improved apparatus for reclaiming gold whereby the gold bearing deposits will give a higher yield of gold at to provide for greater less cost than heretofore; efficiency in the separation of the gold from the gold bearing dirt; and

to make possible the operation at a profit of placer gold deposits of relatively low gold content which would ordinarily be regarded as being unprofitable for commercial reclamation for gold.

A further object of my invention is to provide animproved gold reclaiming machine, preferably of a relatively light which is rugged and wh handling a large quanti in a relatively short in An additional object weight portable nature, ich is capable of efficiently ty of the gold bearing dirt terval of time.

of my invention is to provide an improved apparatus for handling and operating on the gold bearing dirt for reclaiming the gold with improved efiiciency.

- Further objects and advantages of my invention will be more apparent from the following description of one illustrative embodiment of the principles thereof, reference being had to the accompanying drawings in which:

Fig. 1 is a side elevational view of my improved machine.

Fig. 2 is an enlarged sectional elevational view of the main or primary separator portion of my machine.

Fig. 2A is a detail sectional plan view taken along line 2A-2A of Fig, 2.

Fig. 3 is a sectional plan view taken as indicated by line 33 of Fig. 1.

Fig. 4 is a detail sectional view taken along line 44 of Fig. 3.

Fig. 5 is a further detail sectional view taken transversely of the Fig. amalgamating plate.

4 structure just below the Fig. 6 is an elevational view of a typical element of the outer separator spiral as seen in Fig. 2.

Fig. 8 is an enlarged sectional elevational view of the secondary separator portion of my machine.

Fig. 9 is an enlarged detail sectional view of a typical part of the secondary separator portion, the view being taken as indicated byline 93 of Fig. 8. Y

In the drawings, I h

ave illustrated my invention in the preferred form of a portable machine or unit, although it will be understood that stationary units may be employed if desired. This unit comprises a main supporting frame structure A having a fabricated base Ill, uprights I l, top I 2 and appropriate cross-bracing at l3, l4 and at other desirable locations. Frame A carries support wheels l5, which may able for operation on a track IS,

The gold bearing ore or dirt to be separated is first screened or otherwise treated in a well known manner to bring the dirt down to a pulverized form, water being preferably introduced to the dirt during the screening so that the pulverized dirt will readily flow through a hose I! to the suction side of a feed pump B, preferably of the centrifugal type for pumping the mixture of water and dirt upwardly through a pipe 18 for discharge into the hopper C. Pump 13 is operated under power by any suitable prime mover such as the electric motor l9 where a source be of a type suitfixed to a drive shaft operated under power,

as by the motor 26. The pinion 24 also drives a second bevel gear 21 fixed to the upper end of a hollow shaft 28 surrounding shaft 20 for rotation relative thereto in an opposite direction. The shaft 28 is likewise supported on bracket 22 by a bearing 29. 7

Fixed at 30 to the lower end of shaft 28 for rotation therewith is the upper housing member 3| which is -a part of the outer separator spiral D, the upper end of member 3| being provided with an annular trough 32 adapted to receive a supply of water from one or more supply pipes 33, 34, the water supply being regulated by valves 35,

Drivingly secured to the lower end of shaft conduit 20 is the inner separator spiral E, formed of a double spiral core 36, 31. Each spiral core has a spiral groove 38 in its under face for receiving a spiral water supply pipe 39, each pipe having an upper flexible supply extension 40 leading to a funnel portion 4| of an annular trough 42 supplied with water by pipes 43 and trough 32. The trough 42 issecured to conduit 20 and rotates in one direction therewith while the housing member 3| which is secured to shaft 28 rotates in the opposite direction by reason of a drive received from the bevel pinion 24 to a bevel gear 21 fixed to the upper end of shaft 28.

The cores 36, 31, present a passage below conduit 28 for receiving the material therefrom, this passage progressively tapering downwardly as an inverted cone so that the material discharged from conduit 28 will be progressively caught by the gold separating means carried by the cores as will be presently apparent.

Projecting outwardly and downwardly from cores 86, 31 are the rods 45, suitably spaced circumferentially around the cores and threadedly engaging the cores at 45a. for supporting the plates or pans 46, which form a spiral guideway for the dirt. These pans have their inner ends slidably engaged beneath the outwardly projecting ends of core plates 45b secured at 45c to the cores. Plates 45b preferably project inwardly beyond the associated core to catch the material discharged from conduit 28. As a protection against wear, the inner portions of plates 4511 may be provided with a hard rubber coating 45d, vulcanized to the upper surface of these plates. Each of the pans 46 has along one side thereof one or more eyelet brackets 41 adapted to readily receive a rod 45,

this side being overlapped by the next adjacent pan, thereby providing a continuous outwardly and downwardly extending spiral surface from the cores 36, 31. The pans are held from falling downwardly and outwardly from rods 45 by the abutment screws 48 threadedly engaging the outer ends of the rods, the heads of these screws engaging a bracket 41.

Each of the pans 46 is provided with means for separating and collecting the gold from the dirt as it falls down the pans while washed by the water which was mixed with the dirt entering hopper C and which is added by the spray received from pipes 39, the latter for this purpose having suitable nozzles or openings directed downwardly to wash the dirt as it is introduced to the inner ends of plates 45 This separating means, in the illustrated embodiment of my invention comprises a plurality of amalgamating plates or riflies 49 secured to the upper faces of pans 46 and arranged in staggered relationship with one another to battle the travel of the dirt as it moves downwardly and outwardly of the pans 46.

The pans 46 revolve with spiral E as a part thereof so that the dirt does not fall radially along the pans but rather takes a path intermediate a radial and circumferential travel, the amalgamating plates being preferably arranged to lie across this path of travel. These amalgamating plates are adapted to collect the relatively heavy gold particles while the water washes the dirt over these baflle plates. In order to facilitate the gold separating action, these plates are preferably copper coated with mercury, it being recognized that gold has an amnity for mercury.

Each amalgamating plate 48 is preferably readily attachable and removable to a pan 46 by inserting the inner tongue portion 49a through a pan slot 4917 so that the tongue lies beneath the pan with the shank 49c holding the plate 48 in position. Assembly and removal of the plate maybe readily accomplished by tilting the plate as will be readily understood. Each plate 48 has a gold collecting pocket formed by the face 48h bounded by upstanding sides 49d and end 48 the supporting feet 48! preferably disposing the outer edge of the pan substantially parallel to the base of the machine. Each pan may also have one or more gold collecting pockets 489 depressed below the face 48h.

As a further means of holding the overlapped sides of adjacent pans 48 in position during operation of the machine, certain of the plates 48 engage companion slots formed at the overlap, the tongues 49a of such plates serving to connect the adjoining pans 46.

The water supplied to pipes 33, 34 is pumped by a pump 58 through the delivery pipes 52, these pipes having further pairs of supply branches 53, 54 and 55, 56, respectively regulated as to water flowing therethrough by valves 51 and 58 for purposes which will be presently apparent. The supply of water to pump 58 is indicated by a hose 59 preferably flexible to permit the desired degree of movement to the entire machine.

. The lower end of the spiral E has its cores 36, 81 terminating in a spindle 68 which is recessed at 6| to receive the upper end of a plug 62 which rotatably centers the spiral through a bearing 53. The lower end of the plug is fixed within the upper end of a stationary pipe 64. The plug has a laterallyprojecting annular flange 65 provided with a pair of diametrically opposite upwardly opening pockets 66 adapted to receive a roller 61 journalled on a pin for rotatably supporting the spiral E at its lower end.

During rotation of spiral E, the latter is preferably vibrated vertically to assist in the separating action of the gold as the dirt is washed over the plates 49. To this end the spindle 68 has an annular cammed face 68 in engagement with rollers 81, the cam faces being arranged to reciprocate or vibrate the spiral. In order to permit this vibrationwhile driving the shaft conduit 28, the latter has a lower shaft portion 18 drivingly connecting shaft 18 with spiral E. The lower end of shaft 28 has an annular series of drive keys 1| slidably fitting the keyways 12 of shaft portion 18, the keyways being open upwardly and being of sufficient length to provide adequate clearance below keys 1| to accommodate the aforesaid movement.

Referring now to the outer spiral D, the housing member 3| is formed with a lower annular they together form a cylindrical rotating structure as best shown in Figs. 1 and Each spiral element 18 has an opening 19 at its upper end for supporting such element by a pin 88 of smaller diameter than hole 19 whereby each element 18 may be vibrated as will presently be apparent. The pins 88, which are of any suitable type for convenient removal, are mounted between flanges 8| of the housing member 3| and adjacent spiral elements 18 overlap each other at the stepped engaging sides 82 which preferably have a clearance with each other in an increasing degree toward the lower ends of the spiral elements.

Each element 18 has an inwardly projecting spiral trough 83 (see Figs. 6 and 7) arranged below the associated spiral water supply pipe 11 having spray nozzles or holes 84, the floor of each trough 83 having the spaced gold collecting riffles 85 while the side walls are connected by a series of removable gold collecting elements 86, preferably amalgamating plates generally similar in function to the aforesaid plates 49 of the a 1 2,188,971 inner spiral E. In order to increase the gold collecting capacity of these plates, they are formed with a plurality of step-like undercuts 86a, having concave gold collecting pockets 81. These plates are mounted to position, their lower flanges being approximately parallel with the base of the machine. 4

The spiral elements 18 have theirtroughs 83 progressively increasing in width in the downward direction and disposed for rotation closely adjacent the outer peripheral edges of. the pans 46 to receive the water and dirt thrown from the pans as the latter rotate in the opposite direction. As the dirt washes over the rifiles 85 and the amalgamating plates 86 during its travel downwardly in the spiral troughs. gold which escapes collection by the amalgamating plates of the inner spiral is separated and collected by the outer spiral at 85, 86a and 81.

While I do not limit my invention to any particular speeds of rotation of the inner and outer separators E and D, where used in combination, I prefer to rotate these separators relatively slowly in equal opposite speeds of about 45 R. P. M. The speedmay of course vary according to the quality and quantity of the gold bearing dirt be-' ing treated, as' well as by reason of other factors.

During rotation of the outer spiral separator D, the elements 18 thereof are preferably rela-- tively vibrated back and forth about the respec tive axes of pivotal support provided by pins 80, and these elements are additionally vibrated inwardly and outwardly, these vibrations being applied to the lower ends of the spiral elements so that movement at their upper pivoted ends is relatively small. The aforesaid progressively varying clearance will accommodate these relative vibrations between adjacent spiralelements and also facilitate ready outward removal of the spirals for cleaning off and salvaging the gold from the riilles 85 and amalagamating plates 86 by removing pins 88 and permitting each spiral element to slightly drop accompanied by slightly skewing the spiral element to clear the adjacent elements.

In order to rotatably center the lower end of the outer spiral D and to impart the aforesaid vibrations to the spiral elements thereof, I have provided the upper end of the stationary drum 88 of the secondary spiral separator F with a plurality of idler guide rollers 89 spring pressed at 98. These rollers maybe readily outwardly retracted when it is desired to remove or install any or all of the spiral elements 18. Each element 18 has one or more cams 9| formed on its inner face adjacent the lower end thereof, each cam having an inclined face for successive engagement with. a plurality of circumferentially spaced rollers 92 rotatably journalled on fixed axes angled parallel with the faces of cams 9|. During rotation of the outer spiral D, cams 9| progressively engage rollers 92 to impart the aforesaid compound vibrations to the spiral ele-' ments 18.

I prefer to provide further means for acting on the material discharged from the lower ends of the spiral troughs 88 although such further means, herein illustrated ascomprising the secondary spiral separator F, may be omitted if desired.

The separator F is preferably fixed or non-r0 tating and comprises a supporting base 93 carried by the base ID of frame A, this base having a relatively high pitch spirally disposed outer casing 94 terminating upwardly in the aforesaid drum 88. This casing centrally receives the pipe 64 which extends from base 93 to plug 62 and conducts water supplied thereto through branches 66, 66 for radial discharge to the spray pipes 95 having outlets 96 directed toward the spiral slides 91 (see Figs. 8 and 9) These spiral slides 91 receive the dirt and water mixture from troughs 88, the dirt falling by' gravity down the spiral slides as additional water from pipes 95 is sprayed on the slides. The slides v9T are preferably multi-ply burlap which will collect the gold particles as the dirt is washed over a and through the burlap. This burlap is removably suspended between casing 94 and pipe 64 by suitable fastening means 98, 99.

The casing 94 is supported intermediate its length by a spiral floor I88 extended outwardly from pipe 64, this floor having a'series of radially extending goldcollecting riflles llil spaced between steppedamalgamating plates I82 similar to plates 86, the plates I02 being removably mounted between casing 94 and pipe 64 beneath the slides 91 to catch the dirt washed therethrough. The pipe 64 thus cooperates with floor I88 and casing 94 to form a spiral gravity dirt conveyor which is trough-like at cross-sections along its length. a I

If desired, in the interests of conserving the consumption of water, the residue discharged at the bottom of the separator F may be returned to the water pump 58 or to the pump B for recirculation with the material entering the system at pipe I! as will be readilyunderstood.

In the operation of the process and machine as r a whole, the dirt and water mixture is delivered by pump B to hopper C for discharge. downwardly through shaft conduit 28 to the pans 46 of rotating spiral E. This spiral, and also spiral D, preferably rotates in a direction opposite to that experienced with an ordinary spiral drill so spiral troughs 83 ofthe oppositely rotating outer spiral D, the gold being separated and collected by riilles and plates86 while the dirt iswashed from pipes 11.

During the rotation of the spirals D and E, the material treated thereby is continuously agitated, cams 69 vibrating the spiral E and cams 9| vi-' brating the spiral elements 18 of spiral D.

The residue discharged from spiral D' falls by gravity down and through the burlap slide 91 of r the fixed secondary separator F, water sprayed from pipes assisting in the by riffles MI and plates I82.

After the machine has operated a sufficient length oftime depending on the gold content of the dirt being treated-the spiral elements I8 are removed for collecting the gold. Convenient access is thereby obtained for removing trays 46 for the same purpose. The burlap 97 is then burned. and the gold deposit salvaged while the gold collected by riilles IOI and plates I82 may readily be reached for removal by reason of the height between adjacent turns of the open spiral F. The parts are then again assembled with new burlap 91, and the separating process repeated.

The gold may be readily removed from the amalgamating plates in any suitable and convenient manner as by brushing the plates in the presence of water, the mercury, which will ordicollection of gold narily largely brush of! also, being distilled for reclamation.

Instead of using water during the gold reclaiming process in the machine, as hereinbefore set forth, I may employ other forms of fluid such as compressed air to facilitate the separation of gold in a dry pulverized dirt mixture, assisted if desired by magnetic riilles.

Various changes in the details of construction and operation of my machine and in the mode of carrying out my process .will be readily apparent from my disclosure of the principles of my invention, as set forth in the claims appended hereto, and I do not limit my invention to such details and specific process hereinbeforc described.

I claim:

1. Gold reclaiming apparatus comprising a ro tatable separator structure having its axis disposed substantially vertically, means for rotating said separator structure about said axis, said separator structure having an axial spiral core providing a' dirt conducting passage, means for introducing gold-bearing dirt to the upper end of said core for gravity flow downwardly therethrough, the convolutions of said spiral core being spaced from each other to provide dirt passage laterally therebetween, said convolutions progressively diminishing in diameter from the upper end portion of said core toward the lower end portion thereof to catch said dirt flowing downwardly therethrough, a spiral guideway extending laterally of said core for conducting said dirt laterally outwardly from said spaces between the convolutions of said spiral core, and gold collecting means carried by said guideway.

2. A gold separato comprising a spiral core forming a vertically disposed passageway having lateralopenings between the convolutions of said spiral core, means for introducing gold-bearing dirt to the upper end of said core passageway for gravity flow downwardly therethrough and laterally through said openings, a spiral guideway carried by said core for conducting said dirt generally outwardly from said core openings, and gold collecting means carried by said spiral guideway.

3. A gold separator comprising a spiral core having a vertically disposed passageway open laterally between the convolutions of said spiral core, means for introducing gold-bearing dirt to the upper end of said core passageway for conducting said dirt generally outwardly from between said core convolutions, gold collecting means carried by said spiral guideway, and means for rotating said core and spiral guideway as a unit.

4. A gold separator comprising a spiral core forming a vertically disposed passageway having lateral openings between the convolutions of said spiral core, means for introducing gold-bearing dirt to the upper end of said core passageway for gravity flow downwardly therethrough and laterally through said openings, a spiral guideway carried by said core for conducting said dirt generally outwardly from said core openings, gold collecting means carried by said spiral guideway, and a pipe carried by said spiral core, said pipe being spirally wound adjacent the inner edges of the convolutions of said spiral guideway for directing a fluid toward said spiral guideway to facilitate gold collection by said gold collecting means.

5. Gold reclaiming apparatus comprising a separator structure having its axis disposed substantially vertically, said separator structure having an axial core providing a dirt conducting passage, means i'or introducing gold-bearing dirt to the upper end of said core passage for gravity flow downwardly therethrough, said separator structure further including a spirally disposed guideway extending outwardly from and around said core for conducting said dirt generally laterally outwardly from said core passage, said spiral guideway comprising a plurality of pan sectors, support members underlying said spiral guideway and projecting laterally outwardly and downwardly from saidcore to support said pan sectors, said support members being spirally spaced from each other and secured at their inner ends to said core, and gold collecting means carried by said pans.

6. Gold reclaiming apparatus comprising a separator structure having its axis disposed substantially vertically, said separator structure having an axial core providing a dirt conducting passage, means for introducing gold-bearing dirt to the upper end of said core passage for gravity flow downwardly therethrough, said separator structure further including a spirally disposed guideway extending outwardly from and around said core for conducting said dirt generally laterally outwardly from said core passage, said spiral guideway comprising a plurality of pan sectors, a plurality of support rods underlying said spiral guideway and projecting-laterally and outwardly and downwardly from said core, said support members being spirally spaced from each other and secured at their inner ends to said core, each of said pan sectors having one of its outwardly extending edge portions overlying one of said support rods and having the other of its outwardly extending edge portions overlapping and supported by the rod-supported edge portion of an adjacent pan sector, and gold collecting means carried by said pans.

7. A gold separator comprising a spiral core forming a vertically disposed passageway having lateral openings between the convolutions of said spiral core, means for introducing gold-bearing dirt to the upper end of said core passageway for gravity flow downwardly therethrough and laterally through said openings, a spiral guideway carried by said core for conducting said dirt generally outwardly from said core openings, and gold collecting means carried by said spiral guideway, said spiral core being tapered to progressively position successive convolutions thereof inwardly of said passageway to catch the dirt flowing downwardly in said passageway.

8. In a gold separator, a plurality of contiguous spiral elements together forming a substantially cylindrical housing structure having its axis disposed vertically, means carried by the inner wall of each of said spiral elements for lzipllecting gold, means disposed within said ing structure for conducting gold-bearing dirt t each of said spiral elements substantially throughout the lengths thereof, and means for rotating said cylindrical housing structure about said axis during said conduction of the dirt to said spiral elements.

pivotally supporting said spiral elements -for swinging movement thereof relatively to each other.

10. In a gold separator, a plurality of contiguous spiral elements together forming a substan tially cylindrical housing structure having its axis disposed vertically, means for pivotally supporting the upper end of each of said spiral elements for swinging movement relative to each other, means carried by the inner wall of each of said spiral elements for collecting gold, means disposed within said housing structure for conducting gold-bearing dirt to each of said spiral elements substantially throughout the lengths thereof, an annular water storage trough disposed at the upper end of said cylindrical housing structure, a spiral pipe carried by the inner wall of each of said spiral elements for directing water toward the dirt conducted to said elements, and

a flexible water conducting conduit between each of said spiral pipes and said trough adapted to supply water from said trough to said spiral pipes while accommodating said swinging movement of said spiral elements relative to said trough.

11. In a gold separator, a substantially spiral rotatable guideway having its axis extending substantially vertically, means for conducting gold-bearing dirt vertically downwardly along said axis for distribution laterally thereof to the convolutions of said guideway at points spaced along said axis, means for rotating said guideway, a plurality of recessed amalgamating plates carried by the upper faces of said spiral guideway and spaced from each other to baille the dirt during passageway thereof on said spiral guideway from said axis to the outer edges of the convolutions of said spiral guideway.

12. Gold reclaiming apparatus comprising a separator structure having its axis disposed substantially vertically, said separator structure having an axial core providing a dirt conducting passage, means for introducing gold-bearing dirt to the upper end of said core passage for gravity flow downwardly therethrough, said separator structure further including a spirally disposed guideway extending outwardly from and around said core, said core having openings for distributing the dirt to said guideway at points substantially throughout the length of said core passage, said spiral guideway having a slope which extends in a direction radially outwardly and downwardly from said core passage and which has sufficient inclination to cause the dirt to flow by gravity radially of said core passage and circumferentially thereof along a spiral path for gravity discharge from the outer edges of said spiral guideway substantially throughout the length thereof, and gold collecting means carried by said guideway.

13. In a gold separating apparatus, an inner separator having a spiral dirt guideway sloping radially outwardly and downwardly, means for conducting gold-bearing dirt to said guideway, an outer separator having a spiral dirt guideway, the convolutions of which are disposed to position the inner periphery thereof adjacent the outer periphery of the convolutions of the inner spiral guideway to receive dirt from the latter convolutions substantially throughout the length thereof, the convolutions of the outer separator having a relatively greater inclination than that of the convolutions of the inner spiral, and gold separating means carried by said guideways.

14. In a gold separating apparatus, an inner for conducting gold-bearing dirt to said guideway. an outer separator having a spiral dirt guideway adapted to receive dirt outwardly from the convolutions of the first said guideway substantially along the length thereof, and means for rotating said separators simultaneously in opposite directions.

15. In a gold separating apparatus, an inner separator having a spiral dirt guideway sloping radially outwardly and downwardly, means for conducting gold-bearing dirt to said guideway, an outer separator having a spiral dirt guideway, the convolutions of which are disposed adjacent the outer periphery of the convolutions of the inner spiral guideway substantially throughout the length thereof to receive dirt outwardly from the convolutions of the first said guideway, and

gold separating means carried by said guideways, the'convolutions of said spirals extending in opposite directions relative to each other.

16. In a gold separating apparatus, 'an inner rotatable separator having a spiral dirt guideway sloping radially outwardly and downwardly, means for conducting gold-bearing dirt to said guideway, an outer rotatable separator having a spiral dirt guideway, the convolutions of which are disposed adjacent the outer periphery of the convolutions of the inner spiral guideway substantially throughout the length thereof to receive dirt outwardly from the convolutions of the first said guideway, gold separating means carried by said guideways, means drivingly connecting said inner and outer separators for simultaneous rotation thereof in opposite directions, a third nonrotatable separator disposed below said outer separator for receiving dirt therefrom, means for rotatably supporting the lower end of said inner separator on the upper end of said third separator, and gold collecting means associated with said third separator.

17. In a gold separating apparatus, an inner rotatable separator having a spiral dirt guideway sloping radially outwardly and downwardly, means for conducting gold-bearing dirt to said guideway, an outer rotatable separator having a spiral dirt guideway, the convolutions of which are disposed adjacent the outer periphery of the convolutions of the inner spiral guideway substantially throughout the length thereof to receive dirt outwardly from the convolutions of the first said guideway, gold collecting means carried by said guideways, means for simultaneously rotating said separators in opposite directions, a third nonrotatable separator having a spiral dirt guideway adapted to receive dirt from one of the first said separators, means for journalling the lower end of said inner separator on said third separator, gold collecting means carried by said third separator, and means for directing fluid toward said guideways during passage of the dirt therealong. I

18. In a gold separating apparatus, an inner separator having a spiral dirt guideway sloping radially outwardly and downwardly, means for conducting gold-bearing dirt to said guideway, an outer separator having a spiral dirt guideway, the convolutions of which are disposed adjacent the outer periphery of the convolutions of the inner spiral guideway substantially throughout the length thereof to receive dirt outwardly from the convolutions of the first said guideway, gold separating means carried by said guideways, and a spirally wound fluid conducting pipe for each of said separators respectively adapted to direct fluid under pressure toward said spiral guideways.

19. In an ore separator, a spiral core having an axial dirt passageway, a plurality of rods having their inner ends attached to said core, said rods being spaced from each other along the length of said core and sloping downwardly and outwardiy therefrom, a plurality of contiguous pan sectors together forming a spiral dirt guideway, and means removably supporting said pan sectors on said rods.

20. In a gold separatona substantially spiral trough-like conveyor adapted to convey goldbearing dirt by gravity from the upper end of said conveyor to the lower end thereof, gold separating means extending across said. trough-like conveyor at a plurality of points along the spiral length thereof for collecting gold from said dirt. a spirally disposed filter forming a cover for said trough-like conveyor, means for introducing goldbearing dirt to the upper end of said filter for gravity passage along the spiral length thereof and for passage therethrough to said gold separating means, a fluid-conducting pipe extending vertically along the axis of said spiral conveyor, branch pipes radiating from said vertically extending pipe at points along the length thereof for directing fluid toward said spiral filter, and means for introducing fluid under pressure to said vertically extending pipe.

21. In a gold separator, upright spirally extending passage forming means for conducting gold-bearing dirt by gravity downwardly therethrough, said passage forming .means having its spiral convolutions spaced from each other to form a substantially spirally extending opening,

means for conducting said dirt in a series of super-imposed spiral paths extending laterally outwardly and downwardly from said spirally extending opening, and gold collecting means carried by said laterally extending dirt conducting means.

22. In a gold separator, upright spirally extending passage forming means for conducting gold-bearing dirt by gravity downwardly therethrough, said passage forming means having its spiral convolutions spaced from each other to form a substantially spirally extending opening, means for conducting said dirt in a series of superimposed spiral paths extending laterally outwardly and downwardly from said spirally extending opening, said passage forming means having its spiral convolutions progressively inwardly offset to catch the dirt conducted downwardly therethrough for passage through said spirally extending opening, and gold collecting means carried by said laterally extending dirt conducting means. 4

23. In a gold separating apparatus, an inner vertically disposed separator having an inner spiral dirt guideway sloping downwardly and outwardly for gravity flow of gold-bearing dirt, the convolutions of said inner guideway extending for substantially more than 360, means for conducting said dirt to said inner guideway, an outer vertically disposed separator having an outer spiral dirt guideway adapted to receive said dirt from along the periphery of the convolutions of said inner guideway, the convolutions of said outer guideway extending for substantially less than 360 but for substantially the height of said convolutions of said inner guideway, and means for rotating said separators simultaneously in opposite directions.

FRANK W. BRIN'I'NALL. 

